Currently [20th November 1999] showing on BBC2, "Spearhead from Space" is a new start in terms of both style and content. Not until "The Leisure Hive" over a decade later would "Doctor Who" undergo such a revolution in production and storyline. The story is told determined and directly, with no punches pulled, and the result is stunningly effective.The enforced location filming is a great benefit to the show, not because of the look of film- personally I've always found the grainy look of film distracting rather than 'gritty', but because it encourages